66172066 has 4 divisors (see below), whose sum is σ = 99258102. Its totient is φ = 33086032.

The previous prime is 66172063. The next prime is 66172087. The reversal of 66172066 is 66027166.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 33350625 + 32821441 = 5775^2 + 5729^2 .

It is not an unprimeable number, because it can be changed into a prime (66172063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16543015 + ... + 16543018.

Almost surely, 2^66172066 is an apocalyptic number.

66172066 is a deficient number, since it is larger than the sum of its proper divisors (33086036).

66172066 is a wasteful number, since it uses less digits than its factorization.

66172066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33086035.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 66172066 is about 8134.6214417144. The cubic root of 66172066 is about 404.4748892325.

It can be divided in two parts, 661 and 72066, that added together give a palindrome (72727).

The spelling of 66172066 in words is "sixty-six million, one hundred seventy-two thousand, sixty-six".